Magnetic actuator



0. I. PRICE MAGNETIC ACTUATOR July 18, 1944.

j Filed May 6, 1941 m N r R .W% W .M Q4 QM ratentca July 15, 1944 2,353,756 MAGNETIC ACTUATOR Osborne I. Price, Frederick, Md., asslgnor to Magnetic Devices, Inc., Frederick, Md., a corporation of Maryland Application May 6, 1941, Serial No. 392,166

6 Claims.

My invention relates broadly to electromagnetic operating mechanisms and more particularly to a magnetic actuator having improved mounting means for the moving parts of the mechanism and means for improving eillciency in the distribution of magnetic lines of force through the mechanism.

One of the objects of my invention is to provide means for improving the distribution of magnetic lines of force through a, magnetic actuator for eliminating any retarding influence of the magnetic lines with respect to the movement of the moving parts of the actuator.

Another object of my invention is to provide an improved arrangement of pole faces for the magnetic actuator whereby the electrical inertia in movement of the actuator may be reduced and a the time period of operation decreased.

Still another object of my inventionis to provide an improved construction of armature and mounting means therefor in a magnetic actuator.

A further object of my invention is to provide a simplified construction of magnetic actuator which is capable of inexpensive quantity production.

Other and further objects of my invention reside in a construction of magnetic frame and mounting means for an angularly shiftable armature in a magnetic actuator as set forth more fully in the specification hereinafter following by reference to the accompanying drawing, in which:

Figure 1 is a top plan view of the magnetic actuator of my invention; Fig. 2 is a vertical sectional view through the magnetic actuator taken substantially on line 2-2 of Fig. 1 with certain of the parts illustrated partially in section and partially in side elevation; .Fig. 3 is a transverse sectional view taken substantially on line 33 of Fig. 2; Fig. 4 is a perspective view of the movable armature member employed in the magnetic actuator of my invention; and Figs. 5, 6 and 7 are schematic views showing arrange ments for mounting the movable magnetic mem-- her in the magnetic actuator of my invention, Figs. 5 and 6 illustrating arrangements for mounting such member which have 'proven ineffective, while Fig. 7 illustrates the arrangement of mounting the movable member in accordance with my invention.

My invention is directed to a simplified construction Of magnetic actuator which is particularly adapted for the operation of remotely controlled door locks, counters, relays, switches and father devices requiring limited rotary'movement.

. thereby facilitating the operation of the device in a switching system, an electric lock or in any remote control position where space and reliable operation are essential and important fac tors.

, Referring to the drawings in more detail, reference character I designates a plate member of magneticmaterial constituting part of the frame, while reference character-2 designates an opposite-"plate member of magnetic material forming part of the frame Intermediate frame members 3 and 4 of magnetic material extend between the plate members! and 2 and are shaped to conform with the contour of the magnetic actuating system which includes the magnetic actuating winding 5.

The frame member I is centrally apertured at 6 for the passage of the movable armature member as will be'hereinafter more fully described.

The plate member 2 is apertured as represented at I and is provided with pole faces 8 and 9 with respect to which pole faces formed on the operating portion of the movable armature coact. The plate member 2 has an end plate ill of non-magnetic material extending across the aperture 1 therein with a central aperture ll providing bearing means for the projecting end I! of the movable armature member.

The movable armature member has a central cylindrical portion i4 and a frusto-conical portion l5 extending therefrom terminating in a stem I9 with which the projecting end I! is integral and which forms the journal with respect to bearing aperture II in plate l2. The opposite'end of armature I4 is flat as indicated at l6 and projects into the circular aperture 6 in the end plate I as shown. The central stem IT projects from the end l6 of the armature i4 and passes through the aperture 32 through the armature of the magnetic system. A non-magnetic washer is centered over the stem l1 and provides a spacing means between the flat central face l6 of the armature and the plate 3|. The projecting stem IT has a pair of flattened side faces I8 thereon to facilitate engagement between the stem and the device to be angularly shifted or moved.

The stem IQ of the armature carries the transverse magnetic member having pairs of opposed pole faces 2 |-22 extending in opposite directions and angularly disposed as indicated. The transverse magnetic member 20 has pins 23 and 24 projecting therefrom which pins are engaged by coil springs 25 and 25 respectively and which are secured at 21 and 28 to diametrically opposite points in the side walls of the apertured portion I of plate 2. A stop pin 29 projects upwardly from end plate I!) in the path of the transverse magnetic member 20 whereby coil springs 25 and 25 normally maintain the transverse magnetic member 20 in the full line position illustrated in Fig. 3 when the operating winding 5 is deenergized. When operating winding 5 is energized, the transverse magnetic member 20 is shifted to the dotted line position shown at 20 in Fig. 3.

Heretofore angularly shiftable armature members have often been mounted in bearings of the general type illustrated in Fig. 5 wherein the magnetic frame is apertured at for the passage of shaft I! connected with the armature. The magnetic lines of force in returning from the frame member I through armature H tend to drag face ii of the armature against frame I, thereby introducing considerable friction or drag impairing the time of operation of the armature member under remote control. It has been proposed to employ an arrangement illustrated in Fig. 6 in which the frame I may be apertured at 6 for the passage of a portion of the end portion of the armature l4 and to provide a mounting plate 33 of non-magnetic material apertured at 34 for the passage of the projecting end I! of the armature ll. This arrangement is poor as the magnetic lines of force threading the armature and end frame tend to magnetically drag the armature H with respect to the apertured end frame i again introducing such resistance as impairs the operation of the movable actuator.

The disadvantages of the constructions shown in Figs. 5 and 6 are overcome by the method employed in my invention as illustrated in Fig. 7. In this arrangement the plate 31 of magnetic material ismounted upon the end member I and is apertured at 32 for the passage of the stem 11 therethrough. The magnetic lines of force which thread the frame pass through the path provided not only by frame I but also by the plate 3 I. That is to say, the plate of magnetic material which rests upon the frame member 1 provides a wide path for the magnetic lines, precluding magnetic locking and abutment of the end face I! of the armature l4 against the magnetic plate and allowing free rotation of the armature. By providing a path of wide distribution for the magnetic lines, binding of the armature member against the frame is thus prevented. The addition of the magnetic plate 3| forms means for diverting the magnetic lines from the limited path defined by the end frame member and such diversion eliminates the concentrated blocking or looking action for the armature and the frame. That is to say, a better magnetic path is provided through both the frame member I and the magnetic plate 3| distributing the magnetic 11 5 and reducing the concentrated flux which would be the case in the arrangements of either Figs. 5 or 6. By using materials for part 3|, Fig. 'I, that are less magnetic than iron or by varying the cross section of iron, the thrust or fall in an upward or downward position can be controlled as desired on the rotating element. The thrust of the armature is precisely and minutely controlled by the regulation afforded by the path of distribution of magnetic lines through the frame and armature assembly.

The construction of my invention is highly efficient in operation but I realize that modifications may be made and I intend no limitations upon my invention other than may be imposed by the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is as follows:

1. A magnetic actuator comprising a frame structure, an actuating winding associated with said structure, a rotatable armature member disposed within said winding, one end of said frame structure having an opening therein with the wall of the opening closely adjacent to the periphery of the armature member, means for journalling opposite ends of said armature with respect to said frame structure, said means at said first mentioned end of said frame structure constitutingan auxiliary magnetic plate member disposed closely adjacent to the end surface of the armature member, both the end surface of said armature member and the surface of said auxiliary magnetic plate being substantially as extensive as the maximum diameter of said armature member for partially diverting the lines of force from said frame structure through said plate.

2. A magnetic actuator comprising a frame structure, an actuating winding associated with said structure, a rotatable armature member disposed within said winding, one end of said frame structure having an opening therein with the wall of the opening closely adjacent to the periphery of the armature member, means for journalling opposite ends of said armature with respect to said frame structure, said means at said first mentioned end of said frame structure constituting an auxiliar magnetic plate disposed closely adjacent to the end surface of said armature member, both the end surface of said armature member and the surface of said auxiliary magnetic plate being substantially as extensive as the maximum diameter of said armature member for partially diverting the lines of force from said frame structure through said plate, and means secured to the opposite end of said armature for effecting angular movement of said armature when said operating winding is energized.

3. A magnetic actuator comprising in combination, a magnetic frame structure, an actuating winding associated with said frame structure, a rotatable armature, one end of said magnetic frame structure having an opening therein with the wall of the opening closely adjacent to the periphery of the armature, means for joumalling said armature in said frame in position to be angularly shifted under control of said winding comprising at one end: an auxiliary plate of magnetic material apertured vto receive a rotatable extension of said armature and supported by said magnetic frame structure and extending closely adjacent to the surface of said armature, both the end surface of said armature and the surface 91 said auxiliary magnetic plate being substantially as extensive as the maximum diameter of said armature, said auxiliary magnetic plate providing a path for magnetic lines of force supplementing the normal path for lines of force threading said magnetic frame structure and armature;

and at the other end: a non-magnetic plate carcured to said frame and apertured for Journaling one of said shaft extensions and increasing the path-for magnetic flux through the end of said armature, said auxiliary magnetic plate being disposed closely adjacent to the end surface of said cylindrical armature member, both the end surfaces of said cylindrical armature member and the surface of said auxiliary magnetic plate being substantially as extensive as the maximum diameter of said armature member, a non-magnetic plate secured to the opposite end of said frame structure and apertured to form a bearing for the other of said shaft extensions, a transverse magnetic bar carried by said last mentioned shaft extension and having magnetic pole faces on diagonally opposite ends thereof, coacting magnetic faces formed on said frame struc- 1 ture, and means for tensioning said armature to a position of maximum air gap between the pole faces on said bar and the coacting pole faces on said frame structure. 4

5. A magnetic actuator comprising a magnetic frame structure, an actuating winding within said structure, a'substantially cylindrical armature member having mounting shaft extensions on each end thereof, one endof said substantially cylindrical armature member projecting through a correspondingly shaped aperture in the end of said frame structure and establishing a path for magnetic lines through said frame structure and through the side walls-and axially of said armature, an auxiliary magnetic plate secured to said frame and apertured for journaling one of said shaft extensions and increasing the path for magnetic flux through the end of said armature, said auxiliary magnetic plate being disposed closely adjacent to the end surface of said cylindrical armature member, both the end surfaces of said cylindrical armature member and the surface of said auxiliary magnetic plate being substantially as extensive as the maximum diameter of said armature member, a non-magnetic plate secured to the opposite end of said frame structure and apertured to form a bearing for the other of said shaft extensions, said armature including a frusto-conical portion intermediate the substantially cylindrical portion thereof and the shaft extension thereon, a transverse magnetic bar carried by said last mentioned shaft extension adjacent the frusto-conical portion of said armature and having magnetic pole faces on diagonally opposite ends thereof, coacting magnetic faces formed on said frame structure, and means for tensioning said armature to a position of maximum air gap between the pole faces on said bar and the coacting pole faces on said frame structure.

6. A magnetic actuator comprising a magnetic frame having a'magnetic plate at each end thereof, an electromagnetic winding disposed within said frame, a substantially cylindrical armature member having a stem-like extension on each end thereof, one of said magnetic plates having an aperture therein which is substantially closed by the projection of one end of said cylindrical armature therethrough and the other magnetic plate having magnetic pole faces therein, a nonmagnetic plate secured to said last mentioned magnetic plate and apertured to form a bearing for the stem-like extension on said armature,

an auxiliary magnetic plate member secured to said first mentioned magnetic plate and apertured for Join-nailing the stem-like extension of the end of said armature that projects through said first mentioned magnetic plate, both the end surface of said armature and the surface of said auxiliarymagnetic plate member being substantially as extensive as the maximum diameter of said armature member, a transverse magnetic bar carried by one of said stem-like extensions with magnetic faces thereon disposed in alignment with the magnetic pole faces carried by the second mentioned magnetic plate.

OSBORNE I. PRICE 

